Key Messages

• The authors report a perovskite-based artificial leaf (i.e. a fully integrated, wireless photoelectrochemical device) that meets all three of the major criteria for practical solar water-splitting:

  1. Solar-to-hydrogen (STH) efficiency > 10%,

  2. Long-term durability,

  3. Scalability

• They build photoelectrodes using a defect-free, chlorine-doped formamidinium lead triiodide (Cl:FAPbI₃) as the light absorber and a chlorine-doped tin oxide (Cl:SnO₂) electron transport layer (ETL) that is more resistant to ultraviolet (UV) damage.

• Encapsulation is handled with nickel foil and epoxy/other protective layers to shield the perovskite from electrolyte contact. The catalysis (for oxygen evolution, and hydrogen evolution) uses less expensive materials; for example, the oxygen evolution catalyst is NiFeCo oxyhydroxide, and the hydrogen evolution catalyst is a cobalt-molybdenum-sulfide mixture doped with a small amount of Pt (~0.1 wt%) for enhancement.

Key Results

• At the 1 cm² device scale (photoanode), the device shows high photocurrent density and retains 99% of its initial performance after 140 hours of continuous operation in alkaline electrolyte. No lead leaching, and the perovskite absorber remains intact.

• They assemble a mini-module artificial leaf, comprising a 4×4 array of 1 cm² subcells (total 16 cm²), arranged side-by-side with both photoanodes and photocathodes (See above schematic). This achieves a module-level unbiased STH efficiency of 11.2% under 1-sun illumination.

• Scaling up from 1 cm² to the 16 cm² module incurs very small efficiency loss (≈ < 10%) showing good promise for further upscaling.

Innovations / Technical Advances

• Use of Cl-doping both in the PSK absorber (FAPbI₃) and in the ETL (SnO₂): this helps improve stability & reduce defects.

• Replacing UV-sensitive TiO₂ ETLs (common in many perovskite solar devices) with Cl:SnO₂ to reduce UV-induced degradation.

• Effective encapsulation strategy and reactor design (e.g. O-ring type reactor that exposes only the catalysis layer to electrolyte; prevents perovskite or epoxy being in direct contact) to avoid chemical/photocorrosive degradation.

• Using non-noble-metal catalysts (or very low loadings of noble metals) to keep cost and material constraints more favorable.

Implications & Challenges

• This work marks a step closer to commercial viability for artificial leaves: achieving >10 % STH at module size with long durability is rare.

• Because of the modular design, the authors argue that further scaling (towards meter-scale, comparable to current solar panels) could preserve similar efficiencies.

• Remaining challenges include:
  • Ensuring efficient proton transport between the anode and cathode, especially in larger modules,
  • Managing gas separation (H₂ and O₂) in a side-by-side architecture (currently they occupy the same electrolyte side), which may require membranes or external separators.

For more details, please check out our paper “Scalable and durable module-sized artificial leaf with a solar-to-hydrogen efficiency over 10%” in Nature Communications (2025).

Links to cite the article: https://dx.doi.org/10.1038/s41467-025-59597-2

https://www.nature.com/articles/s41467-025-59597-2